ISBB - Q2 - MTAP 1 (MIDTERMS)

1. HDN as a result of Rh incompatibility can be classified as a _______ hypersensitivity while reactions to poison ivy or poison oak is _______

• 1. Atopic or anaphylactic - an Arthus reaction

• Cytotoxic - a cell-mediated response

• Immune complex - an IgE-mediated response

• Delayed - an IgG-mediated response

Answer explanation

EXPLANATION:

↳HDN: Under Type II (cytotoxic) because there is a lysis of red blood cells often due to incompatible maternal antibodies

↳Poison ivy or poison oak

Under Type IV (cell mediate response)

1. The classic complement pathway is initiated by interaction of C1 with _______ whereas interaction of _______ with the carbohydrate groups on microbial cells the lectin complement pathway

• 1. Antigen - mannose

• 1. Factor B - bacterial capsule

• 1. Antigen-IgG complexes - MBP

• 1. Bacterial lipopolysaccharide - C3

Answer explanation

EXPLANATION:

↳Interaction of C1 with the target

target of classical pathway: Antigen-Antibody complex

↳Target of lectin pathway: Mannan Binding Protein

1. Which of the following are NOT true of class I MHC antigens?

• 1. Are essayed by cytotoxic test requiring antibody and complement

• 1. Can usually identified in a few hours

• 1. Include HLA-A, -B, -C, -E antigens

• 1. Are restricted on B cells, macrophages and activated T cells

Answer explanation

EXPLANATION:

↳Letter A is correct because Microlymphocytotoxic test is for MHC class I antigen

↳MHC class I antigens are found on all nucleated cells

↳B cells, macrophages and activated T cells are for MHC class II

1. An antigen found in relatively high concentration in the plasma of normal fetuses and a high proportion in patients with progressive carcinoma of the liver is

• 1. CEA

• 1. Viral antigen

• 1. AFP

• 1. Heterophil antigen

Answer explanation

EXPLANATION:

↳AFP = Alpha Feto protein

Progressive carcinoma of the liver

↳CEA = gastrointestinal tract (colorectal area)

↳Viral antigen and Heterophile antigen are not tumor markers

1. If an individual were genetically unable to make J chain, which igs would be affected?

• 1. IgG

• 1. IgM

• 1. IgA

• 1. IgM and IgG

• 1. IgA and IgM

Answer explanation

EXPLANATION:

↳J chain is a glycoprotein responsible for linking or bridging two or more monomers

● Found only in antibodies with two or more monomeric structure

● IgM is a pentamer (5 monomers)

● Secretory IgA is dimer

1. When immune complexes from the serum are deposited on glomerular basement membrane, the damage to the membrane is caused mainly by

• 1. Lysis complement

• 1. Phagocytosis

• 1. Cytotoxic T cells

• 1. Enzymes released by PMN cells

Answer explanation

EXPLANATION:

↳This item deals with Type II Hypersensitivity

Complement lysis can also contribute but enzymes released by PMN cells is the MAIN cause

1. Antigen presenting cells such as _______ that activate helper T cells must express their surfaces _______

• 1. Cytotoxic T cells - class II MHC antigens

• 1. Macrophages - class II MHC antigens

• 1. NK cells - class I MHC antigens

• 1. B cell7 - class I MHC antigens

Answer explanation

EXPLANATION:

↳To activate or present antigens (extracell-derived),it needs to be presented by class II MHC antigens to the surface of the CD4+ cells (T helper cells).

1. Which one of the following does NOT contain C3b?

• 1. Classic pathway - C5 convertase

• 1. Alternative pathway - C5 convertase

• 1. Lectin pathway - C5 convertase

• 1. Classic pathway - C3 convertase

• Alternative pathway - C3 convertase

Answer explanation

EXPLANATION:

↳C5 convertase in classic pathway = C4b2a3b

↳C5 convertase in alternative pathway = C3bBb3b

↳C5 convertase in lectin pathway = C4b2a3b

↳C3 convertase in classic pathway = C4b2a

↳C3 convertase in alternative pathway = C3bBb

1. Which of the following cytokines stimulates hematopoeitic cells and supports the growth of bone marrow stem cells?

• 1. IL-1

• 1. IL-2

• 1. IL-3

• 1. IFN

• TNF

Answer explanation

EXPLANATION:

↳Interleukin-3 is also known as Multicolony stimulating factor

1. This term refers to the total binding strength of all the binding sites of antigen-antibody complexes

• 1. Zeta potential

• 1. Avidity

• 1. Affinity

• 1. Adjuvants

• 1. Ionic strength

Answer explanation

EXPLANATION:

↳Simple binding strength = Affinity

↳Total binding strength = Avidity